Vaillant condensing boiler freezing - minimising condensate?

BooJewels

ashe said:

Forgive the random honey dipper in the gutter - I was trying to dislodge the stick of ice so that the heating stayed on longer 🤣 that bit at the back though appears as drops land and freeze and it rises up to meet it. I think the only thing that will sort it is the trace kit.

OP, the closed cell stiff isn't that much more expensive than the cheap stuff - Google armacell. It's not crazy cheap but the price difference isn't huge 

Yes, I'd seen Armacell mentioned several times in my research and it doesn't seem to be an unreasonable price - worth it if it saves me this sort of silly drama and going into the garden in snow boots and my nightie!.  

BooJewels

Eldi_Dos said:

@BooJewels

Could the proximity of the water butt have any bearing?
If water butt has frozen it will act as a cold store helping to keep the condensate pipe cold enough for to cause the freezing.

I have no idea, they've always been in the same position.  You could also perhaps argue that the water butt keeps the worst of the wind off the pipe and provides some shelter.  I truly have no idea.  Neither can be moved, so I'll have to work with what I have.

BooJewels

bjorn_toby_wilde said:

Someone mentioned solvent welded joins where the condensate pipe is connected - I can't tell by looking at it - but for now, I'm leaving that particular bit well alone - I know my limitations.

Not sure what the internal pipe from the boiler is, but that exterior photo definitely shows solvent welded black waste, which is what it should be as it’s UV resistant.

It’s not what I was expecting to see. As others have said that shouldn’t freeze up anywhere near as easily as the 21.5mm white plastic stuff that you often see outside.

My son’s is routed outside in exactly the same waste pipe and it hasn’t ever frozen - perhaps I should say yet!!

As mentioned in other replies, I'm now wondering if the problem is starting from the bottom where the pipe touches the grate - there's a little angled connector on the bottom to direct the flow towards the centre of the drain, rather than the edge where the position against the wall places it.  That was full of ice today -  several small pieces melting together into a pipe filling ice cube.  Maybe contact with the grate creates a particular cold spot?

BooJewels

plumb1_2 said:

Just a guess with the OP situation 
1- could be the condensate is dropping onto the grate, and slowly building ice, then gaining height into the pipe, then blocking. Cut the bottom of the pipe so it’s about 40mm up from the grate .
You could drill a 15mm hole in the elbow at the top of the solvent weld fitting, easy access to pour hot water down or a hosepipe.

Belt and braces 
1- Repipe from inside and fit a T branch with a rodding eye instead of the elbow  use 35 or 40 mm pipe
2- Fit stand off brackets down the wall, this will allow you to fit a thicker wall thickness closed cell insulation ( like armaflex).
3- Fit low voltage tracer cable 
4- Keep the pipe off the grating.

Geta local tradesman to do it,

That's what I'm wondering now - there was definitely a lump of ice at the bottom opening earlier today.

If I take that little angled connector off the bottom (I'll not repeat what I've said in other posts), it probably does leave it about 40mm off the grate, so I'll probably leave it off for now.  I'd also wondered about an access method at the top - thinking warm water on the inside would be better as it would sit on top of any ice at the bottom - I could drill a hole in the top, then cover it with a piece of insulation, to remove when access is needed.  

Before I get a tradesman to do anything more complicated I might just try some insulation and leaving the pipe short of the grate and just observe it in colder weather to see if I can identify the cause.  I also wondered about some insulation on the inside of the leaf cover I place over the grate - I've some thick foam pad somewhere and some heavy duty double sided tape.

BooJewels

Yorkie1 said:

grumpy_codger said:

Sometimes it can be easy to disconnect the (white plastic) condensate pipe near the boiler and to collect the condensate temporally to a bucket (that you'll have to empty regularly)

I know the thread has got lots of more technical (and longer-term impact) fixes on it, but just to say that this is what I do. (Have just had to do it today!). The flexible hose comes out of the bottom of the boiler and can be put to one side, with the boiler draining straight into a bucket. 

Mine doesn't have a flexible hose - I already looked and considered that as an option - mine is a rigid pipe that angles to the side, to where the larger bore pipe comes out through the wall.  This plastic pipe weaves between gas and water pipes, so I don't have much working room to pull the connection apart - I decided against even trying.  It might not end well.

BooJewels

Fobeo said:

I had the same problem and solved it by fitting a "Pump House Boiler Buoy Condensate Bypass Valve & Hose Kit BB-1". Check Ebay usually about £30. It provides an alternative outlet for the condensate discharge in winter. I use a 5 litre water bottle and empty it every day. Works fine. 

Something like that is going to be beyond my skills and would perhaps void the warranty I still have on the boiler, so short term, I need maybe a more basic remedy.  But thanks for the suggestion.

WIAWSNB

BooJewels said:

WIAWSNB said:

Blimey, yes, it's astonishing that it's freezing - it looks an ideal setup.
But, once it did freeze, then I think it's pretty clear it never got completely unfrozen again, so subsequent refreezes were much more likely.
So, why did it freeze first time? No idea! The pipe is a good size, so should drain instantly. I guess that a glaze could form on the inside of the pipe wall, and this just builds up with each glug.
Yes, condie is usually dispensed in glugs, I understand because it's via a 'syphon', a bit like a toilet cistern, so that there's always a water 'seal' that prevents combustion gases getting out.
Could there be other water coming out that way? Yes, if the Main Exchanger has failed and is leaking internally, but that would show as a very significant system pressure drop. You don't have this.
Also 'possible' that rain getting in the flue would end up in the combustion chamber and exit via the condie pipe. But unless you have a broken gutter cascading water down on your flue terminal, this is also unlikely.
So, I'd be looking at the bottom of the condensate pipe, and check that it's unrestricted - nowt in t'way.
Then I'd get good quality lagging, and slip a thin layer behind the pipe between it and the wall if theres only a tight gap, and clip the full sleeve over the rest. Almost certainly that's all you'll need. Complete overkill to go heating element in this case, imo.

I don't think there are any faults with the boiler, as everything else appears to be okay - no drop in pressure etc.  I'm wondering if it's occurring from the bottom - if you see later suggestions, as well as your own, maybe the ice is starting where the pipe touches the grate - maybe that is the cold spot that starts the process.  It wasn't blocked there when I first unblocked it yesterday morning - but there's a little angle connector at the bottom that directs the fluid over the centre of the grate, rather than towards the edge where the vertical of the pipe would land it - that was touching the ground, so is perhaps a cold connection. 

But the more I look at it, the more confused I'm getting.  

I agree - there's nothing else amiss with the boiler - you are simply having freezing condensate, and the addition of insulation will almost certainly sort it.
And I suspect it's as Plumb suggested - the issue literally begins at the bottom and builds up. Adding insulation to the pipe should mean that the lukewarm condie should now get to the bottom and prevent any freezing.
Really, nuts to do anything more than this in the first instance - get the good insulation jacket that folk have recommended, try and squish some in between the wall and pipe too, and forget about holes and heating elements.
But, yes, examine what's happening at the bottom of the pipe - consider removing the shoe provided it isn't needed, and ensure there's a gap between the pipe end and the surface below. 
But pretty sure insulation alone will do it - it should allow the condensate to remain well above freezing all the way down. 
You are right to not consider DIYing a condensate pipe alteration at the boiler, if you don't fully understand what's required. Just for info, it's typical that the first condensate pipe connection to the boiler is a snug push-fit and can be dismantled if wished, and subsequent pipe joints are solvented so fixed, but still best avoided - and just not needed. Q - is the boiler in a heated room like a kitchen? If not - say it's in an unheated utility room or garage - then add insulated sleeving to the internal condie pipe too.
And if you can take a pic of the bottom of the pipe in the gulley, it would be interesting. 

BooJewels

Thanks @WIAWSNB - and everyone who has kindly offered their considerable time to try and help me - it's truly appreciated. 

It's difficult when I'm here on my own, with no one else to spit ball ideas with and I don't have the personal knowledge and experience of things that my father or late husband would just have known what to do with.

I'll address your points and try and get a photo tomorrow.  Goodnight.

Eldi_Dos

BooJewels said:

Eldi_Dos said:

@BooJewels

Could the proximity of the water butt have any bearing?
If water butt has frozen it will act as a cold store helping to keep the condensate pipe cold enough for to cause the freezing.

I have no idea, they've always been in the same position.  You could also perhaps argue that the water butt keeps the worst of the wind off the pipe and provides some shelter.  I truly have no idea.  Neither can be moved, so I'll have to work with what I have.

The water butt set up looks like a good thing from a gardening point of view and I would not suggest any physical changes.

If the butt has been full of water and it has frozen it will be pulling down the temperature in that area. What I would look into doing is draining down the butt between November and late March.

The empty butt with a lid on will heat up to a certain extent when it has the sun on it and may provide a warming roost for our feathered friend's. Always nice to see them about.

BooJewels

WIAWSNB said:

BooJewels said:

WIAWSNB said:

Blimey, yes, it's astonishing that it's freezing - it looks an ideal setup.
But, once it did freeze, then I think it's pretty clear it never got completely unfrozen again, so subsequent refreezes were much more likely.
So, why did it freeze first time? No idea! The pipe is a good size, so should drain instantly. I guess that a glaze could form on the inside of the pipe wall, and this just builds up with each glug.
Yes, condie is usually dispensed in glugs, I understand because it's via a 'syphon', a bit like a toilet cistern, so that there's always a water 'seal' that prevents combustion gases getting out.
Could there be other water coming out that way? Yes, if the Main Exchanger has failed and is leaking internally, but that would show as a very significant system pressure drop. You don't have this.
Also 'possible' that rain getting in the flue would end up in the combustion chamber and exit via the condie pipe. But unless you have a broken gutter cascading water down on your flue terminal, this is also unlikely.
So, I'd be looking at the bottom of the condensate pipe, and check that it's unrestricted - nowt in t'way.
Then I'd get good quality lagging, and slip a thin layer behind the pipe between it and the wall if theres only a tight gap, and clip the full sleeve over the rest. Almost certainly that's all you'll need. Complete overkill to go heating element in this case, imo.

I don't think there are any faults with the boiler, as everything else appears to be okay - no drop in pressure etc.  I'm wondering if it's occurring from the bottom - if you see later suggestions, as well as your own, maybe the ice is starting where the pipe touches the grate - maybe that is the cold spot that starts the process.  It wasn't blocked there when I first unblocked it yesterday morning - but there's a little angle connector at the bottom that directs the fluid over the centre of the grate, rather than towards the edge where the vertical of the pipe would land it - that was touching the ground, so is perhaps a cold connection. 

But the more I look at it, the more confused I'm getting.  

I agree - there's nothing else amiss with the boiler - you are simply having freezing condensate, and the addition of insulation will almost certainly sort it.
And I suspect it's as Plumb suggested - the issue literally begins at the bottom and builds up. Adding insulation to the pipe should mean that the lukewarm condie should now get to the bottom and prevent any freezing.
Really, nuts to do anything more than this in the first instance - get the good insulation jacket that folk have recommended, try and squish some in between the wall and pipe too, and forget about holes and heating elements.
But, yes, examine what's happening at the bottom of the pipe - consider removing the shoe provided it isn't needed, and ensure there's a gap between the pipe end and the surface below. 
But pretty sure insulation alone will do it - it should allow the condensate to remain well above freezing all the way down. 
You are right to not consider DIYing a condensate pipe alteration at the boiler, if you don't fully understand what's required. Just for info, it's typical that the first condensate pipe connection to the boiler is a snug push-fit and can be dismantled if wished, and subsequent pipe joints are solvented so fixed, but still best avoided - and just not needed. Q - is the boiler in a heated room like a kitchen? If not - say it's in an unheated utility room or garage - then add insulated sleeving to the internal condie pipe too.
And if you can take a pic of the bottom of the pipe in the gulley, it would be interesting. 

Evening, I've finally got chance to get back to this with a photo etc.

The boiler is in the utility room - which is unheated, but the doorway is immediately adjacent to a very large kitchen radiator and I wedge the door a foot open in winter, so some heat from the rad goes into the utility - so it's a cool room, rather than a cold one (15.3º C just now when I checked).  I don't think it's cool enough to chill the condensate in the interior pipes - in fact, that pipe feels slightly warm to the touch.  But if I end up with any offcuts, I will add them there too.

I must apologise to @Yorkie1 - I do have a flexible length of hose, the section that's currently tucked at the side of the boiler case is in fact flexible when I look at it more carefully.  The rigid piece it joins to would be tricky to disconnect - so it's a moot point anyway - but I just wanted to correct my earlier comment.

This is the bottom end of the pipe and guttering downspout above the grate - the elbow connector was originally attached to the end of the condensate pipe on the right - I think overhand, bending towards the grate.  I twisted it to the side on Monday morning to see if was blocked.  When I looked at it again yesterday it came away in my hand and was full of ice.  As it happens, I can't easily get it back on just now - so I intend to leave it off. 

I also found a short length (about 10") of grey insulation tubing around something larger, so it has stretched, so I will borrow that to put over the last section of the pipe nearest the ground until I can do the job properly.   I have some thin sheet foam too, which I can maybe wrap around it if that doesn't work. 

But hopefully, if it's off the ground and not in contact, it should be less likely to freeze - the condensate should just drip off the open end, fingers crossed.  I need to clean the area a bit better too - I've never got up all the leaves this year, as it has rained so much.  The drain cover has gone back over it again and I'll look at maybe adding some insulation to the underside of that too - need to dig out some materials.